No, React Native can be tested only in mobile simulators like IOS and Android

Update:
Facebook has given a beautiful starter pack for React Native.

[Introducing Create React Native App][1]

Using this, you can run the app in your mobile using expo app(https://expo.io). It syncs using QR code.


  [1]: https://reactnative.dev/blog/2017/03/13/introducing-create-react-native-app

Yes! That&#39;s very much possible with [react-native-web][1]. Here are a couple of related, useful resources to get started:

 - [React Native Web Starter][2]
 - [A guide to combine React and ReactNative into one codebase][3]


  [1]: https://github.com/necolas/react-native-web
  [2]: https://github.com/joefazz/react-native-web-starter
  [3]: https://medium.com/@yannickdot/write-once-run-anywhere-with-create-react-native-app-and-react-native-web-ad40db63eed0

You can use Expo Snack  [https://snack.expo.io/][1] to instantly test your code on a device (using QR code ) or in the browser. For more information, you can go thtrough this article. https://blog.expo.io/sketch-a-playground-for-react-native-16b2401f44a2


  [1]: https://snack.expo.io/

I&#39;m aware that branches don&#39;t really store creator information - and they&#39;re just a pointer to a commit. 

My goal is to be able to clean out my old branches that have been merged back to the main branch, and list branches where this hasn&#39;t been done either. (A clean up). 

This is different to &quot;finding unmerged branches&quot; because I want to find merged branches as well, and I want to do it by author. 

My question is: **Is there a script to list git branches created by me?**

Is there a script to list git branches created by me?

I&#39;ve found the following error when running my android application in android studio. app couldn&#39;t get installed on my device because of this error. Didn&#39;t find the solution :(
please help

&gt; Auth: [GoogleAccountDataServiceImpl] getToken() failed. 
&gt; Status BAD_AUTHENTICATION, 
&gt; Account: &lt;ELLIDED:1913118808&gt;, 
&gt; App:com.android.vending,
&gt; Service: androidmarket com.google.android.gms.auth.be.account.b.d: Long live credential not
&gt; available.

getToken() failed. Status BAD_AUTHENTICATION error

Realizing that React Native apps are designed to be developed / tested using simulators, is it possible to use a web browser to also test an application?

Services such as https://rnplay.org/ exist, however my concern is it&#39;s powered by https://appetize.io/ it might be limited by the # of minutes per month.  I&#39;d also like to utilize free / open-source technology to accomplish this, as compared to a paid screen streaming service.

Along these lines, in order to test the app in a browser, would the app be required to use one or more libraries which allow the app to be run in both React Native and also simply React?  I&#39;d like to find an alternative to this particular approach as I&#39;d like to code for React Native specifically.

Can React Native apps be tested in a browser?

Realizing that React Native apps are designed to be developed / tested using simulators, is it possible to use a web browser to also test an application?
Services such as <a href="https://rnplay.org/" target="_blank" rel="noopener noreferrer">https://rnplay.org/</a> exist, however my concern is it's powered by <a href="https://appetize.io/" target="_blank" rel="noopener noreferrer">https://appetize.io/</a> it might be limited by the # of minutes per month. I'd also like to utilize free / open-source technology to accomplish this, as compared to a paid screen streaming service.
Along these lines, in order to test the app in a browser, would the app be required to use one or more libraries which allow the app to be run in both React Native and also simply React? I'd like to find an alternative to this particular approach as I'd like to code for React Native specifically.

&lt;!-- language-all: lang-js --&gt;

How do I mock sub component in jasmine tests?

I have `MyComponent`, which uses `MyNavbarComponent` and `MyToolbarComponent`

    import {Component} from &#39;angular2/core&#39;;
    import {MyNavbarComponent} from &#39;./my-navbar.component&#39;;
    import {MyToolbarComponent} from &#39;./my-toolbar.component&#39;;
    
    @Component({
      selector: &#39;my-app&#39;,
      template: `
        &lt;my-toolbar&gt;&lt;/my-toolbar&gt;
        {{foo}}
        &lt;my-navbar&gt;&lt;/my-navbar&gt;
      `,
      directives: [MyNavbarComponent, MyToolbarComponent]
    })
    export class MyComponent {}

When I test this component, I do not want to load and test those two sub components; MyNavbarComponent, MyToolbarComponent, so I want to mock it.

I know how to mock with services using `provide(MyService, useClass(...))`, but I have no idea how to mock directives; components;

      beforeEach(() =&gt; {
        setBaseTestProviders(
          TEST_BROWSER_PLATFORM_PROVIDERS,
          TEST_BROWSER_APPLICATION_PROVIDERS
        );
        
        //TODO: want to mock unnecessary directives for this component test
        // which are MyNavbarComponent and MyToolbarComponent
      })
      
      it(&#39;should bind to {{foo}}&#39;, injectAsync([TestComponentBuilder], (tcb) =&gt; {
        return tcb.createAsync(MyComponent).then((fixture) =&gt; {
          let DOM = fixture.nativeElement;
          let myComponent = fixture.componentInstance;
          myComponent.foo = &#39;FOO&#39;;
          fixture.detectChanges();
          expect(DOM.innerHTML).toMatch(&#39;FOO&#39;);
        });
      });

Here is my plunker example;

http://plnkr.co/edit/q1l1y8?p=preview

angular2 test, how do I mock sub component

Im trying to test an upload API but it fails every time: 

**Test Code :**

    $JSONResponse = $this-&gt;call(&#39;POST&#39;, &#39;/upload&#39;, [], [], [
    	&#39;photo&#39; =&gt; new UploadedFile(base_path(&#39;public/uploads/test&#39;) . &#39;/34610974.jpg&#39;, &#39;34610974.jpg&#39;)
    ]);
    
    $this-&gt;assertResponseOk();
    $this-&gt;seeJsonStructure([&#39;name&#39;]);
    
    $response = json_decode($JSONResponse);
    $this-&gt;assertTrue(file_exists(base_path(&#39;public/uploads&#39;) . &#39;/&#39; . $response[&#39;name&#39;]));

&gt; file path is /public/uploads/test/34610974.jpg

**Here is My Upload code in a controller :**

    $this-&gt;validate($request, [
    	&#39;photo&#39; =&gt; &#39;bail|required|image|max:1024&#39;
    ]);
    
    $name = &#39;adummyname&#39; . &#39;.&#39; . $request-&gt;file(&#39;photo&#39;)-&gt;getClientOriginalExtension();
    
    $request-&gt;file(&#39;photo&#39;)-&gt;move(&#39;/uploads&#39;, $name);
    
    return response()-&gt;json([&#39;name&#39; =&gt; $name]);

How should I test file upload in **Laravel 5.2**? How to use `call` method to upload a file?

How to test file upload in Laravel 5.2

I&#39;m currently confuse on how to mock.

I&#39;m using Moq. To mock objects I usually write this way

     var mockIRepo = new Mock&lt;IRepo&gt;();

However, I need to create mock object for my setup.

**Option1**
Is it better to mock my object which only contain properties this way?

     var object = Mock.Of&lt;Object&gt;()

**Option2**
Or this way

     var object = new Mock&lt;Object&gt;()

I&#39;ve read that option 2 has setupproperties which is kinda questionable to me because I could also set the properties in option 1. 

***Then what is the difference? Or is there a better way?***

Mock.Of&lt;Object&gt; VS Mock&lt;Object&gt;()

Hi I&#39;ve been using moq for a while when I see this code.

I have to setup a return in one of my repo.

     mockIRole.Setup(r =&gt; r.GetSomething(It.IsAny&lt;Guid&gt;(), It.IsAny&lt;Guid&gt;(), 
                      It.IsAny&lt;Guid&gt;())).Returns(ReturnSomething);

I have three parameters and I just saw these in one of articles or blog on the net.

What is the use of `It.Is&lt;&gt;` or `It.IsAny&lt;&gt;` for an object? if I could use `Guid.NewGuid()` or other types then why use `It.Is`?

I&#39;m sorry I&#39;m not sure if my question is right or am I missing some knowledge in testing.
But it seems like there is nothing wrong either way.

Why use It.is&lt;&gt; or It.IsAny&lt;&gt; if I could just define a variable?

I have a asp.net core application that uses dependency injection defined in the startup.cs class of the application:  

        public void ConfigureServices(IServiceCollection services)
        {

            services.AddDbContext&lt;ApplicationDbContext&gt;(options =&gt;
                options.UseSqlServer(Configuration[&quot;Data:FotballConnection:DefaultConnection&quot;]));


            // Repositories
            services.AddScoped&lt;IUserRepository, UserRepository&gt;();
            services.AddScoped&lt;IUserRoleRepository, UserRoleRepository&gt;();
            services.AddScoped&lt;IRoleRepository, RoleRepository&gt;();
            services.AddScoped&lt;ILoggingRepository, LoggingRepository&gt;();

            // Services
            services.AddScoped&lt;IMembershipService, MembershipService&gt;();
            services.AddScoped&lt;IEncryptionService, EncryptionService&gt;();

            // new repos
            services.AddScoped&lt;IMatchService, MatchService&gt;();
            services.AddScoped&lt;IMatchRepository, MatchRepository&gt;();
            services.AddScoped&lt;IMatchBetRepository, MatchBetRepository&gt;();
            services.AddScoped&lt;ITeamRepository, TeamRepository&gt;();

            services.AddScoped&lt;IFootballAPI, FootballAPIService&gt;();

This allows something like this: 

    [Route(&quot;api/[controller]&quot;)]
    public class MatchController : AuthorizedController
    {
        private readonly IMatchService _matchService;
        private readonly IMatchRepository _matchRepository;
        private readonly IMatchBetRepository _matchBetRepository;
        private readonly IUserRepository _userRepository;
        private readonly ILoggingRepository _loggingRepository;

        public MatchController(IMatchService matchService, IMatchRepository matchRepository, IMatchBetRepository matchBetRepository, ILoggingRepository loggingRepository, IUserRepository userRepository)
        {
            _matchService = matchService;
            _matchRepository = matchRepository;
            _matchBetRepository = matchBetRepository;
            _userRepository = userRepository;
            _loggingRepository = loggingRepository;
        }

This is very neat. But becomes a problem when I want to unit test. Because my test library does not have a startup.cs where I setup dependency injection. So a class with these interfaces as params will just be null. 

    namespace TestLibrary
    {
        public class FootballAPIService
        {
            private readonly IMatchRepository _matchRepository;
            private readonly ITeamRepository _teamRepository;
    
            public FootballAPIService(IMatchRepository matchRepository, ITeamRepository teamRepository)
    
            {
                _matchRepository = matchRepository;
                _teamRepository = teamRepository;

In the code above, in the test library, **_matchRepository** and **_teamRepository**, will just be **null**. :(

Can I do something like ConfigureServices, where I define dependency injection in my test library project?


how to unit test asp.net core application with constructor dependency injection

With this code:

    import React from &#39;react&#39;;
    import { Link } from &#39;react-router&#39;;
    import { View, NavBar } from &#39;amazeui-touch&#39;;
    
    import * as Pages from &#39;../components&#39;;
    
    const {  Home, ...Components } = Pages;

I get this eslint error:

    7:16  error  Parsing error: Unexpected token .. Why?


Here is my eslint config:

    {
      &quot;extends&quot;: &quot;airbnb&quot;,
      &quot;rules&quot;: {
        /* JSX */
        &quot;react/prop-types&quot;: [1, {
          &quot;ignore&quot;: [&quot;className&quot;, &quot;children&quot;, &quot;location&quot;, &quot;params&quot;, &quot;location*&quot;]
        }],
        &quot;no-param-reassign&quot;: [0, {
          &quot;props&quot;: false
        }],
        &quot;prefer-rest-params&quot;: 1,
        &quot;arrow-body-style&quot;: 0,
        &quot;prefer-template&quot;: 0,
        &quot;react/prefer-stateless-function&quot;: 1,
        &quot;react/jsx-no-bind&quot;: [0, {
          &quot;ignoreRefs&quot;: false,
          &quot;allowArrowFunctions&quot;: false,
          &quot;allowBind&quot;: true
        }],
      }
    }
....
....
What&#39;s the problem?

ESLint Parsing error: Unexpected token

For example: [codepen][1] 
    
    var InputBox = React.createClass({
      render: function() {
        return (
          &lt;input className=&quot;mainInput&quot; value=&#39;Some something&#39;&gt;&lt;/input&gt;
        )
      }
    });


  [1]: http://codepen.io/Enclave88/pen/YqNpog?editors=1010

How to select all text in input with Reactjs, when it focused?

PropTypes and Flow cover similar things but are using different approaches. PropTypes can give you warnings during runtime, which can be helpful to quickly find malformed responses coming from a server, etc. However, Flow seems to be the future and with concepts like generics is a very flexible solution. Also the autocompletion offered by Nuclide is a big plus for Flow.

My question now is which is the best way to go, when starting a new project. Or could it be a good solution to use both, Flow and PropTypes? The problem with using both is that you write a lot of duplicate code. This is an example of a music player app I wrote:

    export const PlaylistPropType = PropTypes.shape({
        next: ItemPropTypes,
        current: ItemPropTypes,
        history: PropTypes.arrayOf(ItemPropTypes).isRequired
    });
    
    export type Playlist = {
        next: Item,
        current: Item,
        history: Array&lt;Item&gt;
    };

Both definitions basically contain the same information and when the data type is changed, both definitions need to be updated.

I found this [babel plugin][1] to convert type declarations to PropTypes, which might be a solution.


  [1]: https://github.com/brigand/babel-plugin-flow-react-proptypes

React PropTypes vs. Flow

In [this documentation][1] of React, it is said that 

&gt; shallowCompare performs a shallow equality check on the current props and nextProps objects as well as the current state and nextState objects.

The thing which I am unable to understand is If It shallowly compares the objects then shouldComponentUpdate method will always return true, as

&gt; We should not mutate the states.

and if we are not mutating the states then the comparison will always return false and so the shouldComponent update will always return true. I am confused about how it is working and how will we override this to boost the performance.




  [1]: https://facebook.github.io/react/docs/shallow-compare.html

How does shallow compare work in react

I have just found that in react `this.setState()` function in any component is asynchronous or is called after the completion of the function that it was called in.

Now I searched and found this blog ([setState() State Mutation Operation May Be Synchronous In ReactJS][1])

Here he found that `setState` is async(called when stack is empty) or sync(called as soon as called) depending on how the change of state was triggered.

Now these two things are hard to digest 
 
1. In the blog the `setState` function is called inside a function `updateState`, but what triggered the `updateState` function is not something that a called function would know about.
2. Why would they make `setState` async as JS is single threaded language and this setState is not a WebAPI or server call so has to be done on JS&#39;s thread only. Are they doing this so that Re-Rendering does not stop all the event listeners and stuff, or there is some other design issue.


  [1]: http://www.bennadel.com/blog/2893-setstate-state-mutation-operation-may-be-synchronous-in-reactjs.htm

Why is setState in reactjs Async instead of Sync?

In react native I have:

    &lt;View style={styles.navBar}&gt;
      &lt;Text&gt;{&#39;&lt;&#39;}&lt;/Text&gt;
        &lt;Text style={styles.navBarTitle}&gt;
          Fitness &amp; Nutrition Tracking
        &lt;/Text&gt;
      &lt;Image source={icon} style={styles.icon}/&gt;
    &lt;/View&gt;

with these styles:

    {
        navBar: {
            height: 60,
            flexDirection: &#39;row&#39;,
            justifyContent: &#39;space-between&#39;,
            alignItems: &#39;center&#39;,
        },
        navBarTitle: {
            textAlign: &#39;center&#39;,
        },
        icon: {
            height: 60,
            resizeMode: &#39;contain&#39;,
        },
    }

This is the effect I get:

[![undesired][1]][1]

This is the effect I want:

[![desired][2]][2]

In the first example, the spacing between items is equal.

In the second example, each item is justified differently. The first item is left-justified. The second item is center-justified. The third, right-justified.

[This question][3] is similar, but it looks like react native does not support `margin: &#39;auto&#39;`. Furthermore, the other answers only work if you only care about left and right justification, but no one really addresses center justification without auto margin.

I am trying to make a navigation bar in react native. The vanilla ios version looks like this:

[![ios][4]][4]  
&lt;sub&gt;(source: [apple.com](https://developer.apple.com/library/ios/documentation/UserExperience/Conceptual/MobileHIG/Art/nav_bar_iphone_2x.png))&lt;/sub&gt;  


How do I do something similar? I&#39;m mainly concerned with centering.

  [1]: https://i.stack.imgur.com/4ACbn.jpg
  [2]: https://i.stack.imgur.com/UkBH9.jpg
  [3]: https://stackoverflow.com/questions/23621650/how-to-justify-a-single-flexbox-item-override-justify-content
  [4]: https://i.stack.imgur.com/SEFcN.png


How to justify (left, right, center) each child independently?

In React Native I use `fetch` to perform network requests, however `fetch` is not an explicitly required module, so it is seemingly impossible to mock in Jest. 

Even trying to call a method which uses `fetch` in a test will result in:

&gt; ReferenceError: fetch is not defined

Is there a way to test such API requests in react native with Jest? 

How to unit test API calls with mocked fetch() in react-native with Jest

I have two different ReactNative-Projects:

 - a) a project from januar 2016 
 - b) a complete new react-native project
   from now (march 20th 2016)

Within the new project the cli tool of react-native contains the command &quot;run-ios&quot; next two &quot;run-android&quot;, but not on the older project from januar 2016. On the older one there is not &quot;run-ios&quot; command available:

    $ react-native run-ios
    Command `run-ios` unrecognized
    Usage: react-native &lt;command&gt;



I already ran &quot;react-native upgrade&quot; without any issues.

How can i get the command &quot;run-ios&quot; also in older projects?



React Native: Command `run-ios` unrecognized

react-native : I have one View and the child of View is an Image , I applied opacity: 0.5 for View and opacity: 0.9 for an Image but it doesn&#39;t apply for Image ,the parent opacity is applying for child , the child doesn&#39;t take independent opacity  

react-native style opacity for parent and child

How do you hide the status bar for iOS or Android when developing with React Native? I&#39;ve imported StatusBar, but I believe there is also StatusBarIOS and a StatusBar for Android.

Hiding the status bar with React Native

Can we test biometric authentication using the simulator?

The iPhone X Simulator shows a menu for Face ID enrollment, but after enabling that, what can I do?

How it will recognize a face for authentication?

[![iPhone X Simulator - Face ID settings][1]][1]

  [1]: https://i.stack.imgur.com/JM5SU.png

Content Type	Original Author	Original Content on Stackoverflow
Question	sean2078	View Question on Stackoverflow
Solution 1 - Testing	Thanigainathan	View Answer on Stackoverflow
Solution 2 - Testing	Umar A.	View Answer on Stackoverflow
Solution 3 - Testing	Ankit Sinha	View Answer on Stackoverflow

Can React Native apps be tested in a browser?

Testing Problem Overview

Testing Solutions

Solution 1 - Testing

Solution 2 - Testing

Solution 3 - Testing

getToken() failed. Status BAD_AUTHENTICATION error

Is there a script to list git branches created by me?

Attributions